Seal for a gas turbine engine

ABSTRACT

A sealing apparatus for a gas turbine engine includes: a first component; a second component positioned in proximity to the first component such that cavity is defined between the first and second components; a resilient seal disposed in the cavity so as to block gas flow between the first and second components, the resilient seal having a first contact surface contacting the first component and a second contact surface contacting the second component; and wherein the resilient seal is configured so as to produce a rolling movement in response to relative movement of the first and second components.

BACKGROUND OF THE INVENTION

This invention relates generally to sealing in gas turbine engines, andmore particularly relates to stationary seals in such engine.

A gas turbine engine includes numerous cavities between adjacentcomponents which must be sealed to prevent leakage of gases from onearea to another within the engine.

Frequently, the adjacent components can experience relative movementfrom a static position, for example as a result of thermal expansion.Typically, the cavities are sealed with resilient seals comprisingrelatively thin sheet material formed into a cross-sectional shapehaving one or more bends. This type of seal is spring-like and flexibleand is able to deflect in response to movement of the components or topressure loads so as to maintain ceiling contact. One knownconfiguration of resilient seal has a W-shaped cross-section and isreferred to as “W-seal”.

Prior art resilient seals such as W-seals can experience failures suchas cracking and fragmentation due to high temperatures and pressurescombined with relative displacement of the adjacent components.

Accordingly, there is a need for resilient seal which can maintainstructural and sealing integrity in the presence of thermal and pressuregradients.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect, this problem is addressed by a resilient sealwhich is shaped so that it can undergo a pivoting or rolling movement inresponse to thermal and pressure loads. This seal configuration can rollwhen compressed and hence reduce stresses.

According to one aspect of the technology described herein, a sealingapparatus for a gas turbine engine includes: a first component; a secondcomponent positioned in proximity to the first component such thatcavity is defined between the first and second components; a resilientseal disposed in the cavity so as to block gas flow between the firstand second components, the resilient seal having a first contact surfacecontacting the first component and a second contact surface contactingthe second component; and wherein the resilient seal is configured so asto produce a rolling movement in response to relative movement of thefirst and second components.

According to another aspect of the technology described herein, asealing apparatus for a gas turbine engine includes: a first component;a second component positioned in proximity to the first component suchthat cavity is defined between the first and second components, aresilient seal disposed in the cavity so as to block gas flow betweenthe first and second components, the resilient seal having a firstcontact surface contacting the first component and a second contactsurface contacting the second component; and wherein a damping elementis bonded to the resilient seal.

According to another aspect of the technology described herein, asealing apparatus for a gas turbine engine includes: a first component;a second component positioned in proximity to the first component suchthat cavity is defined between the first and second components, aresilient seal disposed in the cavity so as to block gas flow betweenthe first and second components, the resilient seal having a firstcontact surface contacting the first component and a second contactsurface contacting the second component, wherein the resilient sealincludes: a first component which forms an annular ring with at leastone split and includes first circumferential corrugations; and a secondcomponent part which forms a closed annular ring and includes secondcircumferential corrugations; wherein the first and secondcircumferential corrugations are nested together.

According to another aspect of the technology described herein, asealing apparatus for a gas turbine engine includes: a first annularcomponent; a second annular component positioned in proximity to thefirst annular component such that cavity is defined between the firstand second components, a resilient seal disposed in the cavity so as toblock gas flow between the first and second components, the resilientseal having a first contact surface contacting the first component and asecond contact surface contacting the second component, wherein theresilient seal separates the cavity into first and second cavityportions, and includes a plurality of bends defining first and secondchambers, wherein the first chamber communicates with the first portionof the cavity, the second chamber communicates with the second cavityportion, the first and second chambers are isolated from each other, andthe chambers are shaped such that, for each chamber, substantially equalsurface areas are facing the opposite cavity portions.

According to another aspect of the technology described herein, asealing apparatus for a gas turbine engine includes: a first component;a second component positioned in proximity to the first component suchthat cavity is defined between the first and second components, aresilient seal disposed in the cavity so as to block gas flow betweenthe first and second components, the resilient seal having a firstcontact surface contacting the first component and a second contactsurface contacting the second component, wherein the resilient sealincludes: a plurality of major bends defining two or more major legsinterconnected by 180 degree bends; and a plurality of 180 degree minorbends within each major leg.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be best understood by reference to the followingdescription taken in conjunction with the accompanying drawing figuresin which:

FIG. 1 is a cross-sectional, schematic view of an exemplary gas turbineengine;

FIGS. 2-6 are schematic, half-sectional views of various embodiments ofrolling seal assemblies;

FIG. 7 is a schematic, half-sectional view of an alternative rollingseal assembly;

FIG. 8 is a schematic, half sectional view of an alternative rollingseal assembly;

FIGS. 9-13 are schematic, half-sectional views of various embodiments ofrolling seal assemblies including pressure deflectors;

FIGS. 14 and 15 are schematic, half-sectional views of rolling sealassemblies including dampers;

FIGS. 16 and 17 are schematic, front elevation and half-sectional views,respectively of two-piece rolling seal assemblies;

FIG. 18 is a schematic, half-sectional view of a balanced rolling sealassembly; and

FIG. 19 is a schematic, half-sectional view of a seal assembly.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings wherein identical reference numerals denotethe same elements throughout the various views, FIG. 1 depicts anexemplary gas turbine engine 10. While the illustrated example is ahigh-bypass turbofan engine, the principles of the present invention arealso applicable to other types of engines, such as low-bypass turbofans,turbojets, turboprops, etc., as well as turbine engines having anynumber of compressor-turbine spools. The engine 10 has a longitudinalcenter line or axis 11.

It is noted that, as used herein, the terms “axial” and “longitudinal”both refer to a direction parallel to the centerline axis 11, while“radial” refers to a direction perpendicular to the axial direction, and“tangential” or “circumferential” refers to a direction mutuallyperpendicular to the axial and radial directions. As used herein, theterms “forward” or “front” refer to a location relatively upstream in anair flow passing through or around a component, and the terms “aft” or“rear” refer to a location relatively downstream in an air flow passingthrough or around a component. The direction of this flow is shown bythe arrow “F” in FIG. 1. These directional terms are used merely forconvenience in description and do not require a particular orientationof the structures described thereby.

The engine 10 has a fan 14, booster 16, high-pressure compressor or“HPC” 18, combustor 20, high pressure turbine or “HPT” 22, andlow-pressure turbine or “LPT” 24 arranged in serial flow relationship.In operation, pressurized air from an exit 26 of the compressor 18 ismixed with fuel in the combustor 20 and ignited, thereby generatingcombustion gases. Some work is extracted from these gases by thehigh-pressure turbine 22 which drives the compressor 18 via an outershaft 28. The combustion gases then flow into the low-pressure turbine24, which drives the fan 14 and booster 16 via an inner shaft 29.

The engine 10 includes within it numerous spaces, many of which areannular, defined by two or more components. Generally, the twocomponents are non-rotating. The spaces are referred to herein as“cavities”. FIG. 2 illustrates a representative cavity 30 definedbetween a first gas turbine engine component 32 and a second gas turbineengine component 34. The cavity 30 is subject to a gas pressuredifferential. There is a need and desire to prevent gas flow frompassing between a first area 36 adjacent the cavity 30 and a second area38 adjacent the cavity 30.

A resilient seal 40 is positioned in the cavity 30. The seal 40 has abody 42. The body 42 may be annular, for example it may be a body ofrevolution about centerline axis 11. The annular shape may be continuousor may include one or more splits. Alternatively, the seal 40 may be anarcuate or straight segment. In other words, its three-dimensional formmay be the two-dimensional shape shown in FIG. 2 extruded along a linearaxis or arc.

The seal has a first contact surface 44 defined by a convex-curve shapecontacting the first component 32 and a second contact surface 46defined by a convex-curve shape contacting the second component 34 toprovide a sealing interface.

The seal 40 may be made from a thin, sheet-like material. Nonlimitingexamples of suitable materials include aerospace alloys such as nickel-,cobalt-, or iron-based alloys. Optionally, the seal 40, or any of theother seals described herein, may be provided with a wear-resistantcoating on some or all surfaces thereof.

The material properties of the seal 40 and its shape are configured toprovide a resilient spring action which urges the first and secondcontact surfaces 44, 46 against the respective components. For example,the body 42 may include branches or legs interconnected by one ormultiple bends 48. The example in FIG. 2 includes three branches or legswhich are generally parallel to each other, interconnected by two bends48 of approximately 180 degrees per bend.

The seal 40 is capable of resiliently deflecting in response to relativemovement of the first and second components 32, 34 in order to maintainsealing contact. For example, if the two components 32, 34 move closerto each other, the seal 40 may compress (contact surfaces 44, 46 movingcloser together), through bending deflection of one or more of the legsor bends 48.

Additionally, seal 40 has a cross-sectional shape which imparts thefunctional ability to pivot or “roll” in response to gas pressure loadsand/or relative movement of the first and second components 32, 34. Thepivoting or rolling movement occurs about an axis labeled “T”, extendingout of the page in FIG. 2. In the instance where the seal 40 is anannular structure revolved about an axis such as centerline axis 11, theaxis T extends in the tangential direction relative to centerline axis11. The direction of movement is illustrated by arrows labeled “P” inFIG. 2. This ability to roll greatly reduces stress in the seal 40 ascompared to prior art seals, thus extending the life of the seal 40. Therolling capability of seal 40 or any other seal described herein may befacilitated by providing curved ends as shown in FIG. 2 (defining thecontact surfaces 44, 46). The radii of curvature of the curved ends maybe selected to tailor the contact pressure and flexural stresses in theseal 40 for a particular application.

As a general principle, the ability to effectively change overalldimension to span the cavity 30 by pivoting or rolling may be impartedby configuring the seal 40 such that its overall length “L” when viewedin section is different from its overall width “L” when viewed insection. Stated another way, an aspect ratio of the sectional dimensionsmay be other than 1:1.

As another general principle, the ability to effectively change overalldimension to span the cavity 30 by pivoting or rolling may be impartedby configuring the seal 40 such that the first and second contactsurfaces 44, 46 are misaligned or offset relative to a direction ofmotion. In the example shown in FIG. 1, and anticipated direction ofmotion would generally be in the axial direction “A” or parallel toengine centerline axis 11. For example, this could occur in response tothermal expansion or contraction.

It can be seen that the contact surfaces 44, 46 are arranged such that asingle line of action in direction A does not pass through both of thecontact surfaces 44, 46. Direction A may be alternatively described as aline or axis oriented normal to the surfaces of both of the components32, 34. The result is that a relative movement of first and secondcomponents 32, 34 parallel to direction A will result in a moment beingimparted to the seal 40 causing pivoting or rolling shown by arrows P.This is in contrast to prior art configurations in which contactingcontact surfaces would generally be aligned along a common line, causingthe seal to deflect solely via compression or expansion.

In the example shown in FIG. 2, the seal 40 may be described as having a“S” shape or a “G” shape. Numerous shapes and retention or mountingconfigurations are possible. FIG. 3 shows an example in which the firstcomponent 32 is provided with an integral hook 50 defining a slot 51which receives a distal end of the seal 40 adjacent first contactsurface 44, and retains the seal 40 in position. This may be necessaryor desirable, for example, to make sure that the seal 40 remains in thecavity 30 even when the engine is not operating and no gas pressuredifferential is present.

FIG. 4 shows an example in which the first component 32 is provided witha separate hook 52 abutting an axially-facing surface 33 of the firstcomponent 32. The separate hook 52 defines a slot 53 which receives adistal end 45 of the seal 40 adjacent the first contact surface 44, toretain the seal 40 in position.

FIG. 5 shows an example in which the first component 32 is provided withan alternate separate hook 54 in the form of an annular body abutting aradially-facing surface 35 of the first component 32. It may beinstalled, for example, using a press-fit with the first component 32.The separate hook 54, in cooperation with first component 32, defines aslot 55 which receives a distal end 45 of the seal 40 adjacent the firstcontact surface 44, to retain the seal 40 in position.

FIG. 6 shows an example in which the first component 32 is provided witha retainer plate 56 and snap ring 58 which engages a groove 60 in thefirst component 32. These components receive a distal end 45 of the seal40 adjacent the first contact surface 44, to retain the seal 40 inposition. The retainer plate 56 can be positioned either on the ID or ODof the seal 40 (i.e. either inboard or outboard), depending on thedirection of the pressure gradient across the cavity 30, so that inoperation the pressure gradient causes an increase in contact pressureon both ends of the seal 40. This concept is applicable for any of theseal variations utilizing a hook or retainer.

FIG. 7 shows a cavity 130 between first and second components 132, 134.The first component 132 includes a seal retainer 156 retained byfastener 158. The seal retainer 156 can have a clearance fit with thefirst component 132, or it can be piloted by a tight tolerance rabbetfit, as needed for a particular application. A resilient seal 140 havinga flat “J” shape extends between the seal retainer 156 and secondcomponent 134. This may be referred to as a “J seal”. The seal 140 hasfirst and second contact surfaces 144, 146 which contact the retainer156 and second component 134, respectively. This seal 140 has theability to pivot or roll in response to gas pressure and/or thermalloads as described above for the seal 40. Optionally, as shown in FIG.7, the seal may have at least one end curved back on itself and the sealretainer may curl around the end of the seal by more than 180°. Thiswill prevent sliding of the seal relative to the retainer, and force anysliding movement to occur at the opposite end of the seal. Interruptedtabs (shown schematically at 145) may be used to form some portion ofthe curled retainer.

FIG. 8 shows a variation of the cavity 130 shown in FIG. 7, with aretainer 156′ and a seal 140′ having a “S” shape.

FIGS. 9-11 illustrate a cavity 230 disposed between first and secondcomponents 232, 234. A seal 240 similar to seal 40 described above isdisposed between the first and second components 232, 234. A pressuredeflector 260 is disposed between the first and second components 232,234 adjacent the seal 240, and serves to reduce the pressure loadimpinging directly on the seal 240. FIGS. 10 and 11 show alternateembodiments 262, 264, respectively of the pressure deflector 260. InFIG. 10, the pressure deflector 262 has a “T” shape when viewed insection, and in FIG. 11, the pressure deflector 264 has an “L” shapewhen viewed in section.

FIG. 12 illustrates a cavity 330 disposed between first and secondcomponents 332, 334. A seal 340 similar to seal 43 described above isdisposed between the first and second components 332, 334. A pressuredeflector comprising two pieces 360 is disposed between the first andsecond components 332, 334 adjacent the seal 340, and serves to reducethe pressure load impinging directly on the seal 340. In this example,each of the components 360 is formed of sheet material bent into an “L”shape and placed opposite to each other such that legs of the L shapesoverlap.

FIG. 13 illustrates a cavity 430 disposed between first and secondcomponents 432, 434. A seal 440 as described above is disposed betweenthe first and second components 432, 434. A pressure deflectorcomprising two pieces 460 is disposed between the first and secondcomponents 432, 434 adjacent the seal 440, and serves to reduce thepressure load impinging directly on the seal 440. In this example, eachof the components has a “T” shape and are placed opposite to each othersuch that legs of the T shapes overlap.

In addition to the pivoting or rolling movement describe above, a sealmay be provided with other means to avoid excessive stress or breakage.

For example, FIGS. 14 and 15 illustrate a means by which a resilientseal may be provided with damping. FIG. 14 shows a resilient seal 540with contact surfaces 544, 546 and including legs interconnected by anumber of bends 548. The bends may turn through more than 90 degrees,for example 180 degrees. A damping member such as a rubber O-ring 566 isplaced adjacent the inside of one or more of the bends 548. FIG. 14shows the resilient seal 540 with a damping member such as a rubberU-ring 568 placed adjacent the outside of one or more of the bends 548.The damping member may be bonded to the resilient seal, for example byadhesive, by thermal bonding, or by molding directly to the resilientseal 540. One example of a suitable damping material is an elastomer.

FIGS. 16 and 17 illustrate how a resilient seal 640 may be provided withgapless sealing around an annulus by providing two or more components.In the illustrated example a first component is an inner seal 668 whichis an annular ring split at one location and includes circumferentialcorrugations 669. It is surrounded by an outer seal 670 which iscontinuous forming a closed annular ring and includes secondcircumferential corrugations 671. The inner and outer seals 668, 670 arepositioned radially adjacent each other such that the firstcircumferential corrugations 669 are nested into the secondcircumferential corrugations 671.

FIG. 18 illustrates a cavity 730 disposed between first and secondcomponents 732, 734. A resilient seal 740 is disposed in the cavity 740and includes a first contact surface 744 abutting the first component732 and a second contact surface 746 abutting the second component 734.The seal 740 includes a central portion 742 defining a spiral or coiledshape which defines first and second chambers 745, 747 that are isolatedfrom each other. The first chamber 745 is in fluid communication with afirst portion 731 of the cavity 730 which would be at a first gaspressure “P1” in operation. The second chamber 747 is in fluidcommunication with a second portion 733 of the cavity 730 which would beat a second gas pressure “P2” in operation, typically different fromfirst gas pressure P1. Seal 740 isolates the cavity portions 731, 733from each other. The chambers 745, 747 are shaped such that, for eachchamber, substantially equal surface areas are facing the oppositecavity portions 731, 733. As a result, the seal 740 is self-balanced,that is, that gas pressure loads in opposite directions will besubstantially equal even if the pressures P1 and P2 are different.

FIG. 19 illustrates a cavity 830 disposed between first and secondcomponents 832, 834. A resilient seal 840 is disposed in the cavity andincludes a first contact surface 844 abutting the first component 834and a second contact surface 846 abutting the second component 834. Theseal 840 includes multiple recursive bends. In the specific exampleillustrated, the resilient seal includes a plurality of major bends 842defining two or more major legs 845 interconnected by 180-degree bends;and a plurality of 180-degree minor bends 847 within each major leg 844.The provision of multiple major and minor bends reduces the bendingdeflection and stress at any given location of the seal 840, for a giventotal deflection.

The seals described herein have advantages over the prior art, namelyincreased service life. The rolling configuration, in particular,significantly reduces the stress on the seal thereby increasing life andSFC, and reliability. Furthermore, in the embodiments using a hook orretainer, the hook or retainer creates contact surfaces between the sealand hook or retainer where the contact pressure increases due to thepressure differentially applied across the seal, thereby enablingincreased sealing capability at higher pressures.

The foregoing has described a seal apparatus for a gas turbine engine.All of the features disclosed in this specification (including anyaccompanying claims, abstract and drawings), and/or all of the steps ofany method or process so disclosed, may be combined in any combination,except combinations where at least some of such features and/or stepsare mutually exclusive.

Each feature disclosed in this specification (including any accompanyingclaims, abstract and drawings) may be replaced by alternative featuresserving the same, equivalent or similar purpose, unless expressly statedotherwise. Thus, unless expressly stated otherwise, each featuredisclosed is one example only of a generic series of equivalent orsimilar features.

The invention is not restricted to the details of the foregoingembodiment(s). The invention extends to any novel one, or any novelcombination, of the features disclosed in this specification (includingany accompanying claims, abstract and drawings), or to any novel one, orany novel combination, of the steps of any method or process sodisclosed.

Further aspects of the invention are provided by the subject matter ofthe following numbered clauses:

1. A sealing apparatus for a gas turbine engine, comprising: a firstcomponent; a second component positioned in proximity to the firstcomponent such that cavity is defined between the first and secondcomponents; a resilient seal disposed in the cavity so as to block gasflow between the first and second components, the resilient seal havinga first contact surface contacting the first component and a secondcontact surface contacting the second component; and wherein theresilient seal is configured so as to produce a rolling movement inresponse to relative movement of the first and second components.

2. The apparatus of any preceding clause wherein the first and secondcontact surfaces are offset relative to an axis mutually normal tofacing surfaces of the first and second components.

3. The apparatus of any preceding clause wherein a sectional area of theresilient seal has an aspect ratio other than unity.

4. The apparatus of any preceding clause wherein the seal has an “S”shape.

5. The apparatus of any preceding clause wherein the seal has a “J”shape.

6. The apparatus of any preceding clause wherein the first and secondcontact surfaces are defined by convex-curved portions of the resilientseal.

7. The apparatus of any preceding clause wherein the first componentincludes a hook which receives a first end of the resilient seal.

8. The apparatus of any preceding clause wherein the hook is defined bya separate component which abuts a surface of the first component.

9. The apparatus of any preceding clause wherein:

-   -   a retainer is connected to the first component; and    -   the first contact surface of the resilient seal contacts the        retainer.

10. The apparatus of any preceding clause wherein the retainer is curledaround one end of the resilient seal by more than 180 degrees.

11. The apparatus of any preceding clause wherein a pressure deflectoris disposed between the first and second components, adjacent theresilient seal.

12. The apparatus of any preceding clause wherein the pressure deflectordefines an L-shape.

13. The apparatus of any preceding clause wherein the pressure deflectorcomprises two opposite-facing elements which overlap each other.

14. The apparatus of any preceding clause wherein the first and secondcomponents are annular components of a gas turbine engine.

15. The apparatus of any preceding clause wherein:

-   -   the first and second components are annular components of a gas        turbine engine; and    -   the first and second components are substantially non-rotating        relative to each other.

16. The apparatus of any preceding clause wherein the resilient sealcomprises a metal alloy.

17. A sealing apparatus for a gas turbine engine, comprising: a firstcomponent; a second component positioned in proximity to the firstcomponent such that cavity is defined between the first and secondcomponents, a resilient seal disposed in the cavity so as to block gasflow between the first and second components, the resilient seal havinga first contact surface contacting the first component and a secondcontact surface contacting the second component; and wherein a dampingelement is bonded to the resilient seal.

18. The sealing apparatus of any preceding clause wherein the dampingelement comprises an elastomer.

19. A sealing apparatus for a gas turbine engine, comprising: a firstcomponent; a second component positioned in proximity to the firstcomponent such that cavity is defined between the first and secondcomponents, a resilient seal disposed in the cavity so as to block gasflow between the first and second components, the resilient seal havinga first contact surface contacting the first component and a secondcontact surface contacting the second component, wherein the resilientseal includes: a first component which forms an annular ring with atleast one split and includes first circumferential corrugations; and asecond component part which forms a closed annular ring and includessecond circumferential corrugations; wherein the first and secondcircumferential corrugations are nested together.

20. A sealing apparatus for a gas turbine engine, comprising: a firstannular component; a second annular component positioned in proximity tothe first annular component such that cavity is defined between thefirst and second components, a resilient seal disposed in the cavity soas to block gas flow between the first and second components, theresilient seal having a first contact surface contacting the firstcomponent and a second contact surface contacting the second component,wherein the resilient seal separates the cavity into first and secondcavity portions, and includes a plurality of bends defining first andsecond chambers, wherein the first chamber communicates with the firstportion of the cavity, the second chamber communicates with the secondcavity portion, the first and second chambers are isolated from eachother, and the chambers are shaped such that, for each chamber,substantially equal surface areas are facing the opposite cavityportions.

21. The apparatus of any preceding clause wherein the resilient seal hasa coil shape.

22. A sealing apparatus for a gas turbine engine, comprising: a firstcomponent; a second component positioned in proximity to the firstcomponent such that cavity is defined between the first and secondcomponents, a resilient seal disposed in the cavity so as to block gasflow between the first and second components, the resilient seal havinga first contact surface contacting the first component and a secondcontact surface contacting the second component, wherein the resilientseal includes: a plurality of major bends defining two or more majorlegs interconnected by 180-degree bends; and a plurality of 180-degreeminor bends within each major leg.

23. The apparatus of any preceding clause wherein the damping element isseparate from the resilient seal and attached thereto by bonding.

24. The apparatus of any preceding clause wherein the damping element isconnected to the seal at a location defining a greater than 90-degreebend in the resilient seal material.

What is claimed is:
 1. An apparatus for a gas turbine engine comprising:a first contact surface contacting a first component of the gas turbineengine; and a second contact surface contacting a second component ofthe gas turbine engine, the first contact surface and the second contactsurface defining a seal, the seal disposed in a cavity formed by thefirst component and the second component, so as to block gas flowbetween the first and second components, wherein the seal is to producea rolling movement in response to a relative movement of the first andsecond components along a longitudinal axis, the rolling movementcausing the seal to pivot about a first axis parallel to a tangentialaxis of the gas turbine engine, wherein the first and second contactsurfaces are offset relative to a second axis mutually normal to facingsurfaces of the first and second components.
 2. The apparatus for thegas turbine engine of claim 1 wherein a sectional area of the seal hasan aspect ratio other than unity.
 3. The apparatus for the gas turbineengine of claim 1 wherein the seal has an “S” shape.
 4. The apparatusfor the gas turbine engine of claim 1 wherein the seal has a “J” shape.5. The apparatus for the gas turbine engine of claim 1 wherein the firstand second contact surfaces are defined by convex-curved portions of theseal.
 6. The apparatus for the gas turbine engine of claim 1 wherein thefirst component includes a hook which receives a first end of the seal.7. The apparatus for the gas turbine engine of claim 6 wherein the hookis defined by a separate component which abuts a surface of the firstcomponent.
 8. The apparatus for the gas turbine engine of claim 6,wherein the hook is to cause an increase in a contact pressure of thefirst end against the first component when a pressure gradient isapplied across the seal, the pressure gradient associated with operationof the gas turbine engine.
 9. The apparatus for the gas turbine engineof claim 1 wherein: a retainer is connected to the first component; andthe first contact surface of the apparatus contacts the retainer. 10.The apparatus for the gas turbine engine of claim 9 wherein the retaineris curled around one end of the seal by more than 180 degrees.
 11. Theapparatus for the gas turbine engine of claim 1 wherein a pressuredeflector is disposed between the first and second components, adjacentthe seal.
 12. The apparatus for the gas turbine engine of claim 11wherein the pressure deflector defines an L-shape.
 13. The apparatus forthe gas turbine engine of claim 11 wherein the pressure deflectorcomprises two opposite-facing elements which overlap each other.
 14. Theapparatus for the gas turbine engine of claim 1 wherein the first andsecond components are annular components of the gas turbine engine. 15.The apparatus for the gas turbine engine of claim 1 wherein: the firstand second components are annular components of the gas turbine engine;and the first and second components are substantially non-rotatingrelative to each other.
 16. The apparatus for the gas turbine engine ofclaim 1 wherein the apparatus comprises a metal alloy.